Elegantly SophisticatedThis series has it all. The Robertshaw 300 Deluxe Programmable thermostats offer state-of-the-art control for commercial and residential applications. Our sleek, flush-to-the-wall design houses feature-laden intelligence. Standard features include Auto Changeover, Permanent Memory Retention during any type of power outage, 3-Hour Temporary Temperature Override and Smart Fan that allows selectable fan operation for each programming period. The 300-227 and 300-229 also incorporate additional relays for the control of dampers or economizers, making them completely flexible for commercial applications. When you add it all up, the 300 Series from Robertshaw is truly in a class by itself.